What you need to know about file compression

The sheer amount of data we generate, share, and move daily means file compression is an important part of doing business. Read on to learn more about how file compression works.

What is file compression?

File compression is a type of data compression that creates a smaller version of a file to allow for easier sharing over a network or internet connection. Generally, it will have a greater impact on image-based PDFs or image files like JPEGs and PNGs, rather than text-only documents.

There are several different compression methods and it depends on the document type as to which one is best. If you use a method like Adaptive Compression, it can analyze the document contents and determine the best type of compression to use.

How does file compression work?

Compression methods like ZIP and RAR scan a file from top to bottom in order to recognize similar or repetitive patterns. Duplicates are replaced with a unique identifier much smaller than the original word, so the overall size of the file is reduced. Below is an example of how this process works from Techterms:

Words in a plain text document might get replaced with numbers or another type of short identifier. These identifiers then reference the original words that are saved in a key within the compressed file. For instance, the word "computer" may be replaced with the number 5, which takes up much less space than the word "computer."

Other methods, like JPEG and JPEG2000, focus on reducing file size by compressing images. The compression engine can reduce image resolution (downsampling to a specific dpi), convert to black and white, and remove any unnecessary data. If the result of this process is smaller than the original, then it is replaced.

Some compressions can be lossless – it retains all details of the original content. Or, it can be lossy – which is where any data that isn’t needed is removed, so it is no longer available in the compressed file.

What are the advantages of file compression?

There are many advantages of file compression, specifically around cloud storage and associated costs:

Frees up storage space on a hard drive or web server

Reduces the amount of time it takes to send something via email or a file-sharing service like Dropbox

Reduces the amount of time it takes to migrate files to the cloud

Minimizes the financial costs of operating a network, since fewer resources are needed to transmit the data

When would I use file compression?

To publish files online for people to download or to send large files as email attachments

To speed up the process of moving a large data set from the desktop to the cloud

To move to a smaller cloud storage solution, which would then reduce any associated costs